Win a 3 Stages of Hell match on Legend difficulty.
Important: You must reach the 3rd stage for the achievement to work. This means the score must be 1-1 before the final round.
Here is what I did:
1. Change The Settings
To make this easy, go to Gameplay Settings and set the Submission Mini-Game to Rapid. Then, adjust the Submission Mini-Game sliders:
Player Button Press Strength: 100
Player Wrong Press Penalty: 0
AI Button Press Strength: 0
AI Wrong Press Penalty: 100
2. Match Setup
Difficulty: Legend.
Match Type: 3 Stages of Hell.
(I selected Normal 1-on-1, Extreme Rules, Hell in a Cell) (Does not matter which match type as long as it has an easy pin or submission win condition option)
Win Conditions: Set all 3 stages to Submission Only.
3. During the Match
Stage 1: Let the AI win. Just stand there and let them pin/submit you.
Stage 2: Win this round. Apply any submission move and the AI will tap out instantly.
Stage 3: Win this final round. Again I applied any submission move for the AI to tap out instantly. Once you win the 3rd stage, the achievement will pop.
Good luck, you're gonna need it!